Property and Casualty Insurance Reserves (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2002
Beginning Property and Casualty Insurance Reserves: [Abstract]
Property and Casualty Insurance Reserves, Gross of Reinsurance at Beginning of Year	$ 1,029.1	$ 1,118.7	$ 1,211.3
Less Reinsurance Recoverables and Indemnification at Beginning of Year	74.5	78.1	77.4
Property and Casualty Insurance Reserves, Net of Reinsurance and Indemnification at Beginning of Year	954.6	1,040.6	1,133.9
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	(31.5)	(33.1)	(24.9)
Total Incurred Losses and LAE	1,221.6	1,305.4	1,285.6
Paid Losses and LAE related to:
Prior Years - Paid Losses and LAE	470.4	503.7	553.2
Total Paid Losses and LAE	1,271.8	1,391.4	1,378.9
Property and Casualty Insurance Reserves, Net of Reinsurance and Indemnification at End of Year	904.4	954.6	1,040.6
Plus Reinsurance and Indemnifcation Recoverables at End of Year	66.2	74.5	78.1
Property and Casualty Insurance Reserves, Gross of Reinsurance at End of Year	970.6	1,029.1	1,118.7
Number of Businesses Acquired				2
GSNIC [Member]
Paid Losses and LAE related to:
Plus Reinsurance and Indemnifcation Recoverables at End of Year	16.9	21.8
Personal Lines [Member]
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	(12.6)	(29.3)	(21.6)
Commercial Lines [Member]
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	(18.9)	(3.8)	(3.3)
Segment, Continuing Operations [Member]
Incurred Losses and LAE related to:
Current Year - Incurred Losses and LAE	1,253.1	1,338.5	1,310.5
Prior Years - Incurred Losses and LAE	(25.2)	(35.0)	(22.0)
Paid Losses and LAE related to:
Current Year - Paid Losses and LAE	801.4	887.7	825.7
Prior Years - Paid Losses and LAE	451.2	472.9	510.8
Segment, Continuing Operations [Member] | Commercial Lines [Member]
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	(12.6)
Segment, Discontinued Operations [Member]
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	(6.3)	1.9	(2.9)
Paid Losses and LAE related to:
Prior Years - Paid Losses and LAE	19.2	30.8	42.4
Segment, Discontinued Operations [Member] | Commercial Lines [Member]
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	(6.3)
Personal Automobile [Member] | Personal Lines [Member]
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	2.2
Homeowners [Member] | Personal Lines [Member]
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	(11.7)
Other Personal Lines [Member] | Personal Lines [Member]
Incurred Losses and LAE related to:
Prior Years - Incurred Losses and LAE	$ (3.1)